Amid increasing concerns about the safety of c-cigarettes, which have become popular among teens and young adults, a new study suggests that vaping may severely impair a person’s heart function and accelerate the aging of arteries and the aorta.

In a study presented on August 12 at the American Physiological Society conference, Cardiovascular Aging: New Frontiers and Old Friends, researchers indicate that within only five minutes of exposure to e-cigarette vapor, mice experienced narrowing of the arteries by 30% and vasodilation decreased.

Researchers tested e-cigarette exposure to mice in both short and long term increments. They studied artery diameter and vasodilation, or the blood vessels ability to widen, as well as aortic stiffness, which is an age-related complication in the heart’s main artery. It is often an indicator of cardiovascular disease.

In the new study, long term exposure, 20 hours per week over 8 months, to e-cigarette vapor increased aortic stiffness by 2.5 times, compared to the control group which was exposed to normal room air.

Researchers warn that even a single exposure to e-cigarettes may be enough to impair vascular function.

Acute exposure resulted in a nine percent decrease in vasodilation. Study authors indicate the vapor damaged aortic endothelium-dependent vasodilation. Endothelium is the membrane found inside the heart and blood vessels. If it is impaired, blood vessels can’t dilate. Endothelium function is considered a significant predictor of stroke and heart attack.